The LCD (Liquid Crystal Display) possesses advantages of thin body, power saving and no radiation to be widely used in many application scope, such as LCD TV, mobile phone, personal digital assistant (PDA), digital camera, notebook, laptop, and dominates the flat panel display field.
Most of the liquid crystal displays on the present market are back light type liquid crystal displays, which comprise a shell, a liquid crystal display panel located in the shell and a backlight module located in the shell. The liquid crystal display panel is the major component of the liquid crystal display. However, the liquid crystal display panel itself does not emit light and needs the back light module to provide light source for normally showing images.
Generally, the liquid crystal display panel is formed by laminating two glass substrates and injecting liquid crystals between the two glass substrates. At the relative inner sides of the two glass substrates, the pixel electrode and the common electrode are respectively located, and the light of backlight module is reflected to generate images by applying driving voltages to control whether the liquid crystal molecules to be changed directions.
In the present LCDs, there will be color washout phenomenon under wide view angle. Although the present skill has utilized the pixel design of the multi domain display to improve the color washout under wide view angle, the color washout phenomenon remains to be obvious. Such situation becomes more obvious in the Vertical Alignment (VA) type LCDs. The present pixel design of improving the color washout under wide view angle requires to set the pixels as Main areas and Sub areas. Different Thin Film Transistors (TFT) are employed to respectively control the Main areas and Sub areas and respectively provide different driving voltages to make the liquid crystals in the Main areas and the Sub areas generate different rotation behaviors. Accordingly, the mixed compensation to the Gamma properties under wide view angle is implemented to realize the objective of improving the color washout. However, more TFTs mean more complicated control circuit and descend of the pixel aperture ratio.
Please refer to FIG. 1, FIG. 2, FIG. 3, together which shows a liquid crystal display pixel structure according to prior art, comprising a lower substrate 100, a passivation layer 200 covering an upper surface of the lower substrate 100, a pixel electrode 300 formed on the passivation layer 200, an upper substrate 400 and a common electrode 500 covering a lower surface of the upper substrate 400. Each pixel comprises four domains. The pixel electrode 300 employs line/space structures with equal gaps in between similar as an optical grating, which requires a photo process for implementing patterning treatment; the passivation layer 200 is directly deposed on the lower substrate 100. Except the via holes, the other areas do not require the photo process for implementing patterning treatment; i.e. basically, the passivation layer 200 is flat. The pixel electrode 300 possesses line patterns. As shown in FIG. 4, FIG. 5, in the foregoing liquid crystal display pixel structure, the liquid crystals in one pixel only have one kind of rotation behavior under the same driving voltage. Therefore, the twisted angles Θ are the same. Although each pixel comprises four domains and provides a certain improvement to the color washout under wide view angle, the effect is not well. The color washout is still serious.